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Comparison of classical method and optimization methods for estimating parameters in nonlinear ordinary differential equation
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  This study is concerned with the estimation of constant  and time-varying parameters in non-linear ordinary differential equations, which do not have analytical solutions. The estimation is done in a multi-stage method where constant and time-varying parameters are estimated in a straight sequential way from several stages. In the first stage, the model of the differential equations is converted to a regression model that includes the state variables with their derivatives and then the estimation of the state variables and their derivatives in a penalized splines method and compensating the estimations in the regression model. In the second stage, the pseudo- least squares method was used to estimate the constant parameters. In the third stage, the remaining constant parameters and the time-varying parameters are estimated by using a semi-parametric regression model. This method is compared with the optimization method, which depends on the algorithm of differential evolution algorithm to estimate unknown parameters. The comparison was made using simulations. The results showed that the results were better to the method based on the differential evolution algorithm.

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Publication Date
Tue May 01 2018
Journal Name
Journal Of Physics: Conference Series
The Approximate Solution of Fractional Damped Burger’s Equation and its Statistical Properties
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Publication Date
Thu Apr 27 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Existence and Uniqueness of The Solution of Nonlinear Volterra Fuzzy Integral Equations
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 In this paper, we proved the existence and uniqueness of the solution of nonlinear Volterra fuzzy integral equations of the second kind.
 

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Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
Development A Method For Production Of Carbon Nanotubes
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In this work chemical vapor deposition method (CVD) for the production of carbon nanotubes (CNTs) have been improved by the addition of S. Steel mesh container (SSMC) inside which the catalyst (Fe/Al2O3) was placed. Scanning electron microscopy (SEM) investigation method used to study nanotubes produced, showed that high yield of two types of (CNTs) obtained, single wall carbon nanotube (SWCNTs) with diameter and length of less than 50nm and several micrometers respectively and nanocoil tubes with a diameter and length of less than 100nm and several micrometers respectively. The chemical analysis of (CNTs) reveals that the main component is carbon (94%) and a little amount of Al (0.32%), Fe (2.22%) the reminder is oxygen. It was also fou

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Publication Date
Sat Dec 13 2014
Journal Name
Environmental Monitoring And Assessment
Estimating the health risks associated with air pollution in Baghdad City, Iraq
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Publication Date
Sun Mar 17 2019
Journal Name
Baghdad Science Journal
Faber Polynomial Coefficient Estimates for Subclass of Analytic Bi-Bazilevic Functions Defined by Differential Operator
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In this work,  an explicit formula for a class of Bi-Bazilevic univalent functions involving differential operator is given, as well as the determination of upper bounds for the general Taylor-Maclaurin coefficient of a functions belong to this class, are established Faber polynomials are used as a coordinated system to study the geometry of the manifold of coefficients for these functions. Also determining bounds for the first two coefficients of such functions.

         In certain cases, our initial estimates improve some of the coefficient bounds and link them to earlier thoughtful results that are published earlier.

 

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Publication Date
Sun Jan 02 2011
Journal Name
Journal Of Educational And Psychological Researches
Differential Item Functioning at the scal of mental health
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At the last years, the interesting of measurement spicilists was increased to study differential item functioning (DIF) wich is reflect the difference of propability true response for test item from subgroups which have equal level of ability . The aims of this research are, inform the DIFat Namers’scale(2009) for mental health to prepare students and detect items that have DIF. Sample research contants (540) students, we use Mantel- Haenzel chi-square to detect DIF. The results are point to there are (26) items have DIF according to gender which are delated form the scale after that.

 

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Publication Date
Sun Mar 13 2016
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
Isolation and Identification of food Probiotic Saccharomyces boulardii by using traditional methods, Vitek 2 system and molecular identification methods.: Isolation and Identification of food Probiotic Saccharomyces boulardii by using traditional methods, Vitek 2 system and molecular identification methods.
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This study was aimed to isolate and identify Saccharomyces boulardii from Mangosteen fruits (Garcinia mangostana L.) by traditional and molecular identification methods To get safe and healthy foods probiotics for use, The isolates and two commercial strains were subjected to cultural, morphological and biochemical tests, The colonies of the isolates were spherical, smooth, mucoidal, dull and white to cream colour on SD agar media .The shape of cells was globose to ovoid and sometimes with budding, in a single form or clustered like a beehive. The isolates and two commercial strains were unable to metabolized galactose and lactose , Results shows that all isolates were unable to utilize potassium nitrate and not grow in the presence of (

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Publication Date
Sat Apr 01 2023
Journal Name
Fluid Phase Equilibria
Prediction of solubility of vitamins in the mixed solvents using equation of state
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Publication Date
Thu Jun 16 2022
Journal Name
Clean Technologies
Performance Evaluation of Roughened Solar Air Heaters for Stretched Parameters
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Publication Date
Thu Jun 16 2022
Journal Name
Clean Technologies
Performance Evaluation of Roughened Solar Air Heaters for Stretched Parameters
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Artificial roughness applied to a Solar Air Heater (SAH) absorber plate is a popular technique for increasing its total thermal efficiency (ηt−th). In this paper, the influence of geometrical parameters of V-down ribs attached below the corrugated absorbing plate of a SAH on the ηt−th was examined. The impacts of key roughness parameters, including relative pitch p/e (6–12), relative height e/D (0.019–0.043), angles of attack α (30–75°), and Re (1000–20,000), were examined under real weather conditions. The SAH ηt−th roughened by V-down ribs was predicted using an in-house developed conjugate heat-transfer numerical model. The maximum SAH ηt−th was shown to be 78.8% as predicted under the steady-state condition

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